mehrdad nikooy | University of Guilan (original) (raw)

Papers by mehrdad nikooy

JOURNAL OF FOREST AND WOOD PRODUCTS (JFWP) (IRANIAN JOURNAL OF NATURAL RESOURCES), 2020

Iranian Journal of Forest and Poplar Research, 2021

تحقیقات جنگل و صنوبر ایران, 2016

Each skid trail construction affects the trees located on the road margins in various extents. Th... more Each skid trail construction affects the trees located on the road margins in various extents. The present study was conducted with the aim to assess the changes in annual ring widths of Beech and Alder trees compared to the control trees inside the Nav District in Asalem forests. To this aim, 40 samples from previously felled Alder and Beech even-age trees were randomly drawn alongside and inside the forest stands. Disks were acquired from the trees and were perfectly polished with sanding machine. They were finally used to measure annual ring widths with an accuracy of 0.01 mm. Effect of species (Alder and Beech) and location (along the skid trail and inside of stand) on the average width of annual ring were analysed using a two-way ANOVA test in a complete randomized design. Results indicated larger average annual ring width of marginal trees (0.20mm and 0.38mm for Beech and Alder trees, respectively) compared to those located inside the stand. Moreover, ANOVA results indicated h...

Journal of Forest Science, 2012

This paper presents research results of the performance of HSM-904 grapple skidder using a full t... more This paper presents research results of the performance of HSM-904 grapple skidder using a full tree harvesting method in a non-native aspen Populus deltoides plantation in even terrain conditions in Shafaroud, Northern Iran. Patch cutting as a silvicultural method was used in the plantation (2,000 ha). To evaluate the newly introduced machine to a ground skidding system in the aspen plantation and the possibility to increase the production rate, an empirical time study was conducted. The elements of the skidding work phase were identified and 58 cycles were recorded for the study. The models for effective time consumption, total productivity and work phase models are calculated. The average load per cycle was 2.2 m3, the average one-way skidding distance was 253 m. The average travel speed of unloaded skidder was 5.53 km·h-1 and the average speed of loaded skidder was lower than the speed of the unloaded one by 2.94 km·h-1. The average output in the study was 7.1 m3 per effective h...

caspian journal of environmental sciences, 2020

This study was carried out in the Saravan Forest Park in north of Iran. The sound level measureme... more This study was carried out in the Saravan Forest Park in north of Iran. The sound level measurements were performed at 12 stations and at distances of 3, 100, 200, 400 and 1000 m from the sound source with three replicates, in the summer and in traffic hours from 10 AM to 2 PM an area without tree cover was selected as the control station. The results indicated that sound intensity at first distance (3 m) with the mean of 77.81 decibel (dB) exceeds the national standard of Iran. In this study, the first significant decrease in the sound intensity was obtained at a distance of 100 m, with the highest reduction of 26 dB for station 10, while the lowest decrease was found at station 11 with 8 dB. In an overall summary, distances less than 200 m are not suitable for tourism accommodation. The average sound intensity at distances in comparison with the permissible value indicate that the park does not currently have any noise pollution at more than 200 m in summer.

International Journal of Environmental Research and Public Health

Tree felling is recognized as one of the most difficult and physically demanding work phases in m... more Tree felling is recognized as one of the most difficult and physically demanding work phases in motor–manual wood harvesting, during which maintaining good posture can avert unnecessary loadings to the spine and the consequent musculoskeletal disorders to forestry professionals. This study aimed to (a) quantify the impact of posture selection by means of heart rate measurements and (b) analyze its interactions with the anthropometric and personal information of study subjects. Thirteen forest workers were asked to fell thirty trees in each of the four most common body postures during motor–manual forest operations: (i) stooping, (ii) flexed stooping, (iii) squatting, and (iv) half kneeling. Posture had a significant impact on the amount of heart strain measured as mean heart rate during work (HRwork), heart rate increase over resting heart rate (ΔHR), and relative heart rate index (HRR). The most popular position among the forest workers was flexed stooping, which also caused the mo...

تحقیقات جنگل و صنوبر ایران, 2017

Protection of forest soil is one of key factors in having sustainable productive forests. In this... more Protection of forest soil is one of key factors in having sustainable productive forests. In this research extent and intensity of soil disturbance due to extraction of logs of felled trees (20.5 m3/ha) were studied in Nav-e Asalem forest in Gilan province. After finishing the skidder logging operations, soil disturbance were studied by point-transect sampling method and visual assessing. Results indicated that about 19 ± 6.2 percent of surface soils were disturbed due to winching of logs that 11.3 percent of them disturbed with shallow intensity and 7.7 percent disturbed with deep intensity. The extent and intensity of soil disturbance were decreased by increasing distance from skid trail. The extent and intensity of soil disturbance were increased by increasing of ground slope. Soil bulk density in the shallow disturbed soils (1.29 g/cm3) and deep disturbed soils (1.44 g/cm3) were increased 2.4 and 14.3 percent, respectively, than control soils. Soil bulk density of disturbed area...

تحقیقات جنگل و صنوبر ایران, 2015

Using machines such as hydraulic excavator and bulldozer is very common in construction of forest... more Using machines such as hydraulic excavator and bulldozer is very common in construction of forest roads, and their costs have a major share from the hourly cost of a road construction project. Therefore, the estimation of production and costs of each apparatus production unit is regarded as a powerful mean for appropriate management and optimum usage of the facilities. In Liashisera district situated in 27th watershed of Amlash, a combination of two machines of hydraulic excavator and bulldozer were used in the road construction due to economic and environmental considerations. Majority of excavation operations were initially carried out by hydraulic excavator, and the bulldozer was used in the final stage to correct the slope and prepare the road bed for pouring sand scattering. The components of daily construction work including useful and useless times, technical and personal delays were assessed by time study technique in various slope categories. The results showed the average ...

Environments, 2021

In this study the influence of forest management on the characteristics of snags and tree cavitie... more In this study the influence of forest management on the characteristics of snags and tree cavities in the Hyrcanian forests of Iran was investigated. In particular, the effect of two sylvicultural treatments (shelter wood and single-tree selection) was assessed in comparison to protected stands. The abundance, diameter, height, and degree of decay of snag species, and the characteristics of birds excavated and natural cavities (number and height from the ground level) were measured by systematic plots in each stand. The results showed that the abundance, species diversity, and size of snags in both of the sylvicultural treatments were significantly lower than the protected stands. The number of birds excavated and natural cavities on thicker snags with moderate decay was significantly higher than other decay classes. Abundance, species diversity, size of snags, and number of tree cavities in the single-tree selection stands were significantly higher than sheltered-wood stands.

Sustainability, 2021

Background: Poplar tree plantations for wood production are part of a worldwide growing trend, es... more Background: Poplar tree plantations for wood production are part of a worldwide growing trend, especially in moist soil sites. Harvesting operations in moist sites such as poplar plantations require more study for detailed and increased knowledge on environmental and economic aspects and issues. Methods: In this study, the effects of soil moisture content (dry vs. moist) on productivity, cost, and emissions of greenhouse gases (GHG) caused by operations of different harvesting systems (chainsaw-skidder and harvester-forwarder) were evaluated in three poplar plantations (two in Italy and one in Iran). Results: The productivity (m3 h−1) of both systems in the dry sites were significantly higher (20% to 30%) than those in the moist sites. Production costs (€ m−3) and GHG emissions (g m−3) of both systems in the dry sites were also significantly lower than those in the moist sites. The productivity of the harvester-forwarder system was about four times higher, and its production cost wa...

The paper investigated the effects of ground-based skidding on soil physical properties. For this... more The paper investigated the effects of ground-based skidding on soil physical properties. For this purpose, soil disturbance following skidding was assessed for four levels of traffic intensity and three levels of slope gradients; each combination replicated three times. Soil samples were collected from the depth interval of 0-10 cm before and after traffic with a Timberjack 450C skidder in control areas and on skid trails. All soil response measures revealed detrimental compaction and porosity conditions in the skid trails, particularly on steep slopes >20%. The results clearly showed that most of the potential impact occurred after the initial passes. Substantial increases in bulk density appeared right after the first two skidder passes on steep slopes. Regardless of traffic intensity, however, dry bulk density and microporosity increased and total porosity, macroporosity, void ratio and soil moisture content decreased considerably regardless of slope gradient. Nonetheless, com...

Madera Y Bosques, 2015

Se realizo un extenso estudio de campo para examinar la influencia de la intensidad de trafico (5... more Se realizo un extenso estudio de campo para examinar la influencia de la intensidad de trafico (5, 10 y 15 ciclos de arrastre) (es decir, pasar de ida y vuelta en la pista de arrastre) y de la pendiente del terreno de arrastre (0-10, 10-20 y mas de 20)% en la compactacion del suelo, remocion suelo del bosque y la profundidad de la huella despues de la tala. Los resultados mostraron que la densidad de masa seca y la profundidad de las raices se incrementan conforme lo hacen la frecuencia del trafico y la pendiente y que la cobertura de suelo disminuyo. Dentro de cada tratamiento de trafico, la compactacion del suelo aumento con el incremento de la pendiente del terreno, se observaron diferencias significativas en la densidad aparente seca entre la pendiente menor a 20% y la mayor a 20%. La densidad aparente se acerca a su valor critico despues de 15 ciclos. Se observo la formacion de surcos en el suelo en los tratamientos de 10 ciclos. La perturbacion del suelo aumento significativam...

An extensive field trial was set up to examine the influence of traffic intensity (5, 10, and 15 ... more An extensive field trial was set up to examine the influence of traffic intensity (5, 10, and 15 skidding cycles) (i.e. pass back and forth on the skid trail) and skid trail slope (0-10, 10-20, and > 20)% on soil compaction, forest floor removal, and rut depth after logging. The results showed that dry bulk density and rut depth increased with the increase of traffic frequency and slope, but floor coverage decreased. Within each traffic treatment soil compaction raised with the increase of skid trail slope, so that significant differences in dry bulk density were observed between slopes lower than 20% and those greater than 20%. Bulk density has become quite close to the critical value after 15 cycles. We observed soil rutting on the treatments started with 10 cycles. Soil disturbance increased significantly on slopes with less than 20% inclination with a dry bulk density of 1.157 g cm -3 after 5 cycles compared to 0.923 g cm -3 on slopes lower than 10%. In addition the litter ma...

Caucasian alder is a large tree and one of the commercial species in the Caspian forests. We inve... more Caucasian alder is a large tree and one of the commercial species in the Caspian forests. We investigated the wound healing rate (WHR) and compared the diameter growth (DG) of 66 wounded and 66 unwounded alder trees 15 years after selected logging in these forests. The conditions of the wounds after 15 years were as follows: 56.1% had closed, 25.7% were open, and 18.2% had decayed. The mean WHR was 4.95 cm/yr, ranging between 0 and 17.3 cm/yr, and DG of wounded trees was 13.3% lower than in unwounded trees. The WHR and DG were related to the size, intensity and location of the wound, stem diameter (diameter at breast height; DBH), and ratio of wound size to stem basal area. The WHR in middle-aged trees was more than in young and older trees. The reduction in DG of wounded alder trees was only observed in the DBH range below 58 cm. Wounds that were larger than 100 cm in area significantly reduced diameter growth of alder trees. Height of wound from ground level had significant negati...

Land, 2021

The growth and quality of natural seedlings are important goals of forest management in uneven-ag... more The growth and quality of natural seedlings are important goals of forest management in uneven-aged high stands. In this study, the recovery process of the physical and chemical properties of soil, as well as growth variables of beech seedlings on the skid trails after skidding operations in three time periods (10, 20, and 30 years) were investigated in the Hyrcanian forests of Iran. Results revealed that the soil chemical properties (organic C, total N, and pH) were fully recovered after 20 years, while soil physical properties (bulk density, porosity, and penetration resistance) were not yet fully recovered even after 30 years. The values of growth characteristics (stem and root system) and the quality index of beech seedlings were not statistically different from those of the control area ones after 20 years. According to our findings, the process of recovering soil characteristics after forest operations is long and takes more than 30 years. Considering the effect that soil comp...

Journal of forest science, 2017

Masumian A., Naghdi R., Zenner E.K., Nikooy M., Lotfalian M. (2017): Comparison of different eros... more Masumian A., Naghdi R., Zenner E.K., Nikooy M., Lotfalian M. (2017): Comparison of different erosion control techniques in the Hyrcanian forest in northern Iran. J. For. Sci., 63: 549–554. The aim of this study was to evaluate the effects of closure best management practices (BMPs) on runoff volume and soil loss on skid trails that received two densities of soil cover mats and were located on two slope gradients in an Iranian temperate mountainous forest. The treatments included combinations of three closure BMPs (water bar only, water bar + sawdust, and water bar + hardwood slash), two amounts (densities) of mats (7.5 and 15 kg·m–2), and two levels of slope gradients (≤ 20% and > 20%). Results showed that the water bar treatment was the least effective erosion control treatment, followed by the hardwood slash and sawdust treatments. Averaged over mat densities and both slope gradients, the average runoff rates and amounts of soil loss from the skid trails with the water bar trea...

Harvest traffic with heavy equipment causes damage to forest soils. Whereas increased soil damage... more Harvest traffic with heavy equipment causes damage to forest soils. Whereas increased soil damage has been reported with increasing harvest equipment traffic and on increasing slope gradients, it is unclear how much soil damage is caused by different directions of skidding. We examined the effects of traffic frequency, skid trail slope and skidding direction on the dry bulk density and total porosity of skidding trail soil in an Iranian temperate forest. The studied treatments included combinations of three different traffic frequencies (3, 7, and 12 passes of a rubber-tired skidder), three levels of slope (<10%, 10–20% and >20%) and two skidding directions (uphill and downhill). The impact on soil properties was greatest during the skidder initial passes. On steep slopes, only three skidder passes were required to cause substantial increases in soil bulk density relative to control plots, regardless of skidding direction. Independently of the traffic frequency and trail slope...

caspian journal of environmental sciences, 2019

Forest roads are one of the main affecting factors on diversity and composition of plant species.... more Forest roads are one of the main affecting factors on diversity and composition of plant species. This study aimed to investigate the effects of forest road on composition of tree communities of forests in west of Guilan Province, Iran. Therefore, in two age classes (0-10 and 10-20 years old) of forest roads with five different distances from the road edge, totally, 240 sample plots (150 square meters) were taken by line transect method. The results showed that the relative importance of Fagus orientalis, Quercus castaneifolia and Acer velutinum trees on roads with lower age (0-10 years old) was higher than those with higher age (10-20 years old). The results also indicated that on the newly-constructed roads, the presence of pioneer species (Alnus subcordata and A. cappadocicum) became lower than the other species by moving from the roadside into the forest. In this study, the species importance values of A. subcordata, A. cappadocicum, and A. velutinum decreased from roadside to t...

European Journal of Forest Research, 2017

Lime-trees (Tilia begonifolia Stev.) have countless ecological and economical values in the north... more Lime-trees (Tilia begonifolia Stev.) have countless ecological and economical values in the northern forests of Iran. Bole wounds on residual trees are commonly caused by logging. The healing ability of bole wounds and the effect of bole wounds on diameter growth in lime-trees were assessed in a natural mixed uneven-age stand. The susceptibility to decay in relation to the wound severity was also evaluated. Condition and location of lime-trees before and after selective logging were determined through systematic plot sampling. The position of each lime-tree was identified on a topographical map using the global positioning system. After 10 years from wound occurrence, tree and wound characteristics were also re-measured. Overall, 68 stems (9.7 stem ha−1) of lime-trees were found in the sampled area, 25 stems (36.8%) were damaged in the form of bole wound, and 43 stems (63.2%) were undamaged. Statistical differences between wounded or non-wounded lime-trees in terms of diameter and h...

Roads are built in forests for two main reasons, but always in function of management of forest e... more Roads are built in forests for two main reasons, but always in function of management of forest ecosystems, and these reasons are to provide access to the forest area for transportation mobility and wood extraction. This creates a relatively even network in the forest. This topic has received much attention in recent years due to its function and effect on forested rural landscapes and the related environment. Forest road network is important for various types of functional use, such as the interface between forested lands and roads. The aim of this study is to assess the effects of road existence and use on the occurrence of tree dieback and on the composition of the tree community in three forest areas (two in Italy and one in Iran). The effort to determine the dynamics of the effects caused by road use was done by examining the changes in stand structure and abundance of species. As demonstrated by the results, the edges (20 m) of the forest road network are a fine mosaic compose...